1. Field of the Invention
The present invention relates generally to a wireless sensor network. More particularly, the present invention relates to a method, apparatus and system for displaying topology information of a wireless sensor network.
2. Description of the Related Art
A wireless sensor network includes sensor nodes and a sink node. Each sensor node comprises a miniaturized radio transceiver that can collect data through a sensor, process the collected data through a processor, and send the processed information. The sink node collects information from the sensor nodes and transfers the same to the outside. Wireless sensor networks are used primarily for remote information collection rather than for communication, and can be used to develop various applications with scientific, medical, military, and commercial purposes.
FIGS. 1A and 1B illustrate various topologies of sensor networks.
In FIG. 1A, a node Node1 is the head, center, of a cluster. The center is referred to as a cluster head. Nodes Node2 to Node6 are connected to the cluster head and lower-level nodes of the cluster head, and the node Node3 is a child node of the node Node2.
In FIG. 1B, a node Node1 is the cluster head, and nodes Node2 to Node7 are lower-level nodes of the cluster head. The nodes Node3 and Node4 are child nodes of the node Node2, and the node Node7 is a child node of the node Node6.
The nodes Node1, which are cluster heads, in FIGS. 1A and 1B can be sink nodes in their cluster networks. The sink node transfers data collected from the wireless sensor network to the outside, providing information regarding nodes of the wireless sensor network to the user. Thereto, sensor network observation software is normally used. The sensor network observation software graphically displays on the screen information collected by sensors regarding temperature, illumination, humidity, higher-level nodes, and cluster heads, using information from the sink node collecting data from the sensors interconnected through radio frequencies. The sensor network observation software collects and processes sensor node data from the sink node, and displays nodes in a single cluster through formation of connections between the nodes. For example, when sensor nodes equipped with an illumination sensor and humidity sensor send sensed data to the sink node, the sensor network observation software connected to the sink node processes and uses the sensed data.
However, to operate the sensor network observation software, the user has to specify locations of sensor nodes, and whenever a node is added, the user has to arrange the newly added node in the network. In the case of a ubiquitous sensor network including many nodes, the problem of duplicate visualization of nodes may occur with the increasing number of nodes, making it difficult to convey accurate information. Hence, it is necessary to develop a technique enabling efficient visualization of a large number of nodes.